链表30分求调

#include<bits/stdc++.h>
#define ll long long 
using namespace std;

struct Node{
	int data;
	Node *next;
}; 
Node *head,*p;
int n,x,y,k;
void Add(int x,int y){
	p=head->next;
	while(p!=NULL){
		if(p->data==x){
			Node *z;
			z=new Node;
			z->data=y;
			z->next=p->next;
			p->next=z;
			return;
		}
		p=p->next;
	}
}
void Question(int x){
	p=head->next;
	if(p->next==NULL){
		printf("0\n");
	}
	while(p!=NULL){
		if(p->data==x){
		printf("%d\n",p->next->data);
		return;
		}
		p=p->next;
	}
	
}
void Delete(int x){
	p=head->next;
	while(p!=NULL){
		if(p->data==x){
			p->next=p->next->next;
			return;
		}
		p=p->next;
	}
}
int main(){
	scanf("%d",&n);
	head=new Node;
	p=new Node;
	head->next=p;
	p->data=1;
	p->next=NULL;
	for(int i=1;i<=n;i++)
	{
		scanf("%d%d",&k,&x);
		switch(k){
			case 1:
				scanf("%d",&y);
				Add(x,y);
				continue;
			case 2:
				Question(x);
				continue;
			case 3:
				Delete(x);
				continue;
		}
	}

	return 0;
}